it was paris. paris saved his life, literally saved his life. >> safer: we moved on to the sorbonne, paris's ancient university. it changed the lives of many other americans. >> mccullough: charles sumner was here in 1838. and he had come to broaden himself, to become a more civilized human being. >> safer: sumner was a young boston lawyer who found himself studying alongside students from colonial africa. >> mccullough: he saw that they were dressed exactly like the other students. they were treated like everybody else. and he wrote in his journal that night, "i wonder if the way we treat black people at home has more to do with what we've been taught than the natural order of things." and it was... it was an epiphany for him. >> safer: sumner went home convinced of the evils of slavery, and became a major voice in the campaign to abolish it. >> mccullough: so you talk about dropping a stone in the pond that sends out ripples. this one young man, one american, studying here at the sorbonne, has th